TV antennas and radar interference?

[floyd]

Hi

Considering fitting a TV antenna for this season and I am wondering whether the glomex style antennas should/need to be mounted clear of a radome? Have no intention of trying to use TV while under way- I am thinking more about whether the antenna would interfere with the radar signal. On the glomex web site the mounting for the antenna only puts it up 15cm, which is pretty much smack in line with the radome...

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[steverow]

Shouldnt make too much difference really.

There are a couple of issues:

Whether the TV antenna has enough "metal" on it to modify the polar pattern of the radar transmitter and give you a blind spot,

Whether the TV front end (RF amp) will be overloaded by the much higher power of the Radar and cause the TV to go "low gain".

On the first, well possibly, but the effect would probably only be very noticable at extreme range. All bits of metal surrounding any transmitting antenna have an effect upon it, but this effect can be reduced by not having anything near in exact multiples of 1/4 wavelength. This is a bit difficult with a radar where the wavelength is extremely short.
I should discount it really.

On the second, the frequency difference between your TV and radar is quite large.
Radar frequency is about ten times higher than TV reception. The selectivity of the TV tuner should be sufficiently good to reject any signal at this frequency.

I would be more worried about battering my TV tuner with 25watts of marine band VHF, the fourth harmonic of which is nicely in TV band IV, but even that, given a well tuned and filtered transmitter, into an antenna with a low VSWR and a reasonable quality TV tuner, wont really present a problem.


Steve.




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[Nick2]

Allegedly there is very poor TV reception in Hythe and we could only get local Southampton TV.

We nolonger have a telly on the boat.......

Hope to see you about

Nick


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[steverow]

In Swansea Marina SWMBO watches Cornation St, East enders, Hollyoaks, etc etc, on a freeview box with a piece of wet string as an antenna.
Great reception here.

Steve.



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[gonfishing]

Only because we are in line of site of Kilvey hill the main transmitting mast for Swansea !!!!


Julian

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[terryw]

Nick,
We had the same problem in Ocean Village. Got a digibox and now have about 40 crystal clear channels.

Terry

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[woodie1000]

Terry - could you explain that set up to me? We have had a TV aerial on the boat and have always got pretty mixed reception (we're in Port Solent but maybe moving to Ocean Village). Where did you get the digibox from (is it just the basic sky version), what did you need as an aerial/feed into it?

Cheers


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[terryw]

Adam,
It is a standard "Free to View" digi box from Currys. I bought the Grundid box because it is very small, and was on offer at about £80, but you can get tham alot cheaper. It is connected to the standard Glomex aerial, via the standard co-ax lead. I have connected the box to the TV using Scart, and as I have said the picture and sound are perfect.
If you are considering this setup check there is reception in your area. I know it does not work in Poole (or at least didn't last year)

Have you already got a place in OV? The Berthing Master told me recently they are now full and starting a waiting list.

Terry

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[Wiggo]

Steady, Terry! We use the same system, though I have a new Strong 5000 digibox from Richer Sounds - £50 and it runs on 12V. We were convinced it didn't work in Weymouth, but it turns out when you move port, you need to let the thing retune itself to the local tramsmitter - only takes a couple of minutes...

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[terryw]

Graham,
I realise that, but Poole does not have Free to View reception.

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[Wiggo]

Furry Nuff. Took us a week of watching snow to cotton on to the retuning thing...

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[woodie1000]

Terry - great - thanks for that. I will have a look for these on the web/when I'm out and about!

Yes, we reserved a berth some time ago so should be all set for the move - probably over Easter weekend.

Will likely see you there!



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[Planty]

Reception on North Side of OV is not as good as where Terry is for some reason. We have aerial amplifier and panasonic digibox and does play up occasionally with a short stutter on "bad signal". Dialled some of this out by placing the digibox on a small stand so that more of the heat generated could dissipate from bottom as well as top. Saw on another forum somewhere that the panasonic boxes are prone to overheatng and this badly affects reception. Even with this though the overall reception north side is not brilliant. Look forward to seeing you soon Paul

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